Stop Light Without Warning.

[happygoron 2]

Having some engine issues lately.

 

Though this may be unrelated on Thursday morning it failed to start. Had a look that afternoon and saw she wasn't sparking. Noticed a bolt was loose on the distributor cap, take it off and see some sign of fluid ingress, clean it up and she fires first time. All good.

 

Driving home last night, engine up to temp, all guages showing normal, oil checked that morning and up to top line on dipstick. Slow down for some traffic lights and all of a sudden oil pressure plummets and warning + stop light comes on. Hazards on engine off, sat in outside lane of quiet dual carrigeway. Think f*** this and try starting her, she fires first time and all guages show normal. Drive carefully home.

 

Starts fine this morning and oil level was still fine. I (maybe stupidly) start leaning towards it being an electrical glitch as happens so often with these cars. Drive it this morning, all fine. Take it for a fair run up the valleys and back this evening, all fine. Just as I get home (literally 50m from the house) stop light on, just as yesterday.

 

She's been running a bit off lately, been having the odd unreproducible engine "shunt", as though she's labouring/kangarooing, only at cruising revs/speed. This seemed to be due to small throttle changes such as lifting off and then she'd jerk a little. It had me thinking but I wasn't overly worried as it wasn't a regular thing.

 

Oil and water levels are fine, pressures and temps have been normal too. She sounds a little tappety at lower revs but has done for as long as I remember and doesn't seem to affect her, she pulls fine all through the rev range.

 

Any ideas as what could be causing all this and if they are linked? I'm stumped.

[hexhamstu 9]

Is it while under braking or just normal driving?

[happygoron 2]

Is it while under braking or just normal driving?

 

I assume I was braking both times as the first time I was coming up to a red light and the other my drive. However I am not 100% sure, I may have been coasting.

Edited October 24, 2009 by happygoron

[Anthony 1,000]

Doubt they're linked to be honest.

 

When the STOP and oil pressure light comes on, is the oil pressure gauge also reading zero, or is it still reading normally (which would be lowish at hot idle). The pressure gauge and warning light are on different senders and wiring, so if you have the light on and showing no pressure on the gauge, it's likely there is a genuine oil pressure issue - whereas if the gauge still reads, it's probably a wiring issue with the oil pressure switch wiring, more than likely grounding against the block.

[hexhamstu 9]

Could try taking the sump off and checking the oil pump for debris, also changing the oil and filter will help.

[Masekwm 2]

I can't believe you stopped in the outside lane of a dual carriageway

[Galifrey 1]

I can't believe you stopped in the outside lane of a dual carriageway

 

Think he means outside as in left?

 

May be wrong tho

[happygoron 2]

I do mean outside as in right, though as I said I was stopping at lights with a few cars in the inner lane stopping me moving over when the dash did a christmas tree act and all stopped. Didn't have a massive amount of choice, hence why I tried to restart it straight away!

 

I don't recall what happened yesterday Anthony, however today both the gauge and light came on which as you say indicates a problem rather than electrical issue. I'm leaning towards oil pump issue at the moment. Oil filter was changed earlier in the year and it burns oil at enough of a rate for it to have been clean oil in the sump, but I'd better get it off and check. Not sure exactly what I'll be looking for mind....

 

Couldn't really be happening at much worse a time, I'm mega busy for the next few weeks and could do with a car!

[Anthony 1,000]

Check the crank pulley bolt (22mm) is tight - these can occasionally come loose, and if it does, it will do really odd things with oil pressure as the oil pump drive relies on friction from that bolt.

 

Otherwise, if it is only when you're stopping / in traffic, it's not just that the revs are dropping down too low is it? Low revs equals low oil pressure, and low enough revs will bring the light on.

[steve@cornwall 100]

I do mean outside as in right, though as I said I was stopping at lights with a few cars in the inner lane stopping me moving over when the dash did a christmas tree act and all stopped. Didn't have a massive amount of choice, hence why I tried to restart it straight away!

 

I don't recall what happened yesterday Anthony, however today both the gauge and light came on which as you say indicates a problem rather than electrical issue. I'm leaning towards oil pump issue at the moment. Oil filter was changed earlier in the year and it burns oil at enough of a rate for it to have been clean oil in the sump, but I'd better get it off and check. Not sure exactly what I'll be looking for mind....

 

Couldn't really be happening at much worse a time, I'm mega busy for the next few weeks and could do with a car!

 

Make sure the engine loom is well away from the exhaust manifold and not chafing anywhere, eg on the cam cover- may be shorting the guages.

[Anthony 1,000]

Make sure the engine loom is well away from the exhaust manifold and not chafing anywhere, eg on the cam cover- may be shorting the guages.

If you short the oil pressure gauge wire, it reads full pressure though, not zero... hence my first question about whether the gauge and light agreed with each other.

[hexhamstu 9]

anyone know why the pulley for the oil pump chain relies on friction? Is it in case the oil pump seizes or something? I mean if the oil pump seizes engine is probably fubar anyway.

[happygoron 2]

Ok, got the car to my old mans where all the tools are. Plan of action when I next get time and the rain holds off is so:

 

• Tighten the crank pully bolt. I assume I'll have to remove the belt cover to get to it and it needs locking off. What is the best way to lock it? I've been searching and I see that you can lock it against the casing webbing but this isn't really strong enough...
  
• Drop sump and check for any fouling and debris. Change filter too. To drop the sump I assume it is: drain oil, undo bolts making a note of which goes where, tap sump off, clean up and clean surfaces for refitting, replacing gasket when I do. I assume the spacer can remain in place? What should I be looing for in the bottom end?
  

 

From reading oil pump failure is very rare so I'm hoping it isn't that. If neither of these fix it then I'm gonna be stumped, the annoying this is it isn't reproducible and the car does drive, though obviously I don't intend on doing so again until I have carried out the above.

[large 33]

I had a problem like this (still have it from time to time). Give the brown multi plug (the one by the A.F.M.) a clean and spray with WD40.

 

I would have thought that if the oil pump was u/s it would not have fixed it self.

 

If you are local to me I could give you a hand if neded.+ I have a couple of oil pumps .

[happygoron 2]

There is no brown multiplug, I assume Anthony chopped it out before I bought it. Drove me nuts trying to find it mind! I have already changed the oil pressure gauage wire a few months back when that was flickering.

 

Does both the guage drop and light come on for you too Huw?

 

I was locl to you last night, up in Aberdare! Sadly I'm back in Swansea now.

[large 33]

I thought that may be the case (no plug) but was not 100% so I put it up.

 

TBH I can't fully remember as it has been over 6 months that it did it last. I think it was the oil presure warning light and the stop light. It also may have been the warter temp light as well.

[taylorspug 7]

As far as tightening the lower pulley bolt goes, you dont need the cambelt cover off, its the bolt that holds the alternator pulley onto the crank that youu need to tighten. Also get a lever bar into the flywheel via the gearbox bellhousing to lock it off. Id do this then start the engine up andd run it up to temp for a bit. As at the moment its hard to tell if the problem is electrical or oil pressure. Tbh if the oil pressure light is coming on because the engine is knackered, it should come on alot.

 

Also check the oil pressure sender and switch for leaking, as if the oil pressure light switch is leaking oil it can cause the light to flicker on.

[hexhamstu 9]

oil pressure is dropping and the stop light comes on for me everytime I brake hard and oil pressure drops at high RPM. You done any more with this neil?

[Masekwm 2]

My 8v tells me it's got max oil pressure every time I touch the loud pedal, then settles back to normal once I lift off...

[happygoron 2]

The pressure guage has given me grief before and I've replaced the wire. That along with both the sensor and warning switch giving the same result is making me lean against it being an electrical thing, as anthony rightly pointed out. My problem is I can do all the checks I listed above but not know if I've fixed it, I drove best part of 80 miles between the two occourances I described without a hiccup!

 

I've not got anywhere no, and probably won't will the weekend after next. If a nice afternoon shows this week I may have a look at the bolt but I fly to prague on saturday and not back till the friday so it'll be the weekend after that I really get to have a good look and drop the sump. Yours sounds like this bolt slipping problem though stu.

 

Need to get a new sump gasket for that too, I'm not paying GSF delivery prices!

Edited October 26, 2009 by happygoron

[happygoron 2]

Right, tightened that crank pully bolt today, it turned a little but not much. Went for a drive, blackpool illuminations came on less than 2min from the house. Car restarted and drove normally for another 5 min, then I parked it up again. Still no untoward noises that I can hear and still seems to pull fine.

 

Next plan is to get some engine flush and run it through, changing the oil filter too in case it's just sludged up a little in the sump (trying to avoid dropping it till I have to). That'll have to wait till next weekend now though as can't get any oil flush now.

[hexhamstu 9]

Right, tightened that crank pully bolt today, it turned a little but not much. Went for a drive, blackpool illuminations came on less than 2min from the house. Car restarted and drove normally for another 5 min, then I parked it up again. Still no untoward noises that I can hear and still seems to pull fine.

 

Next plan is to get some engine flush and run it through, changing the oil filter too in case it's just sludged up a little in the sump (trying to avoid dropping it till I have to). That'll have to wait till next weekend now though as can't get any oil flush now.

Halfords?

[happygoron 2]

Halfords?

 

Rang, didn't have any. Bumper to bumper in town are getting me some and I'll get it later in the week and do it saturday.

[happygoron 2]

Got some flushing oil last week, foxed by the wind and rain that time. Weather still bad today but decided to have a go and the battery was flat! It's punishing me for leaving it in the drive for so long! Gonna have been off the road for over a month now, all for the want of two oil changes (if that sorts it!). Oh for a workshop....

[happygoron 2]

Finally had a dry morning. Dropped the old oil, filled with flushing oil, let it idle for 40min, dropped that and saw it was pretty black, changed filter and filled with new oil. Has ran fine for about 15 miles since so fingers crossed, though it'll be a while before I'm confident it's sorted. Will probaly repeat the above in a few hundred miles.

 

Out of interest how does flushing oil work? I notice it has a massive change in viscosity with temperature.